Plasma-sealant wobble paddle

ABSTRACT

An apparatus is configured to process a work piece and includes a robotic arm, a sealant discharger, and a plasma discharger. The robotic arm includes a distal end that is rotatable with respect to an axis of the robotic arm. The sealant discharger includes a sealant outlet configured to discharge sealant while the sealant outlet is at a first point. The sealant discharger is mounted on the distal end such that the first point is located on the axis. The plasma discharger includes a plasma outlet configured to discharge plasma while the plasma outlet is at a second point that is located a distance apart from the axis. The plasma discharger is mounted on the distal end such that the second point is rotatable around the axis.

CROSS REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.13/971,097 filed Aug. 20, 2013, the disclosure of which is herebyincorporated by reference in its entirety.

BACKGROUND

The present disclosure relates to apparatuses and methods of assemblingcomponents and, more particularly, apparatuses and methods of cleaningand applying substances on components prior to assembly.

In an assembly line in which components are handled, robots aregenerally used to handle components of various shapes. It is oftennecessary to program the robot to be aware of the shape of thecomponents and to tailor the movement of the robot to such a shape. Suchan operation may involve applying a type of substance (e.g., paint,sealant) on the component, inserting bolts/screws into holes of thecomponent, or the like. In conducting these processes, it can bedifficult to program the robot to be aware of the complex shapes of thecomponents, and methods and apparatuses that can facilitate this processare useful.

SUMMARY

In a first example, an apparatus is configured to process a work piece.The apparatus includes a robotic arm, a sealant discharger, and a plasmadischarger. The robotic arm includes a distal end that is rotatable withrespect to an axis of the robotic arm. The sealant discharger includes asealant outlet configured to discharge sealant while the sealant outletis at a first point. The sealant discharger is mounted on the distal endsuch that the first point is located on the axis. The plasma dischargerincludes a plasma outlet configured to discharge plasma while the plasmaoutlet is at a second point that is located a distance apart from theaxis. The plasma discharger is mounted on the distal end such that thesecond point is rotatable around the axis.

In a second example, a method of processing a work piece using a roboticarm is provided. The robotic arm includes a distal end that is rotatablewith respect to an axis of the robotic arm. The robotic arm includes aplasma discharger and a sealant discharger mounted to the distal end.The plasma discharger includes a plasma outlet configured to dischargeplasma. The sealant discharger includes a sealant outlet configured todischarge sealant. The work piece includes a surface. The methodincludes a step of positioning the plasma discharger and the sealantdischarger such that the sealant outlet is located at a first pointwhich in proximity to the surface and the plasma outlet is located at asecond point which is in proximity to the surface. The first pointdefines a discharge point for the sealant. The second point defines adischarge point for the plasma. The first point is positioned on theaxis and the second point is rotatable around the axis. The methodfurther includes a step of moving the distal end such that the axis ismoved along a predetermined path on the surface while dischargingsealant from the first point so as to apply sealant on the surface. Themethod further includes a step of pivoting the distal end such that thesecond point traces the predetermined path during the step of movingwhile discharging the plasma such that the plasma is applied on thesurface along the predetermined path. The second point traces thepredetermined path ahead of the first point along an entirety of thepredetermined path.

In a third example, a method of processing a work piece including asurface is provided. The method includes a step of discharging sealantfrom a first point along an axis that is oriented perpendicularly to thesurface. The first point is in proximity to the surface such that thesealant is applied on the surface. The method further includes a step ofdischarging plasma from a second point that is located a distance apartfrom the axis. The second point is in proximity to the surface such thatplasma is applied on the surface. The method further includes moving theaxis while discharging the sealant such that the sealant is applied onthe surface along a predetermined path thereon. The method furtherincludes pivoting the second point around the axis while discharging theplasma during the step of moving such that the second point is movedalong the predetermined path and the plasma is applied on the surfacealong the predetermined path. The second point traces the predeterminedpath ahead of the first point along an entirety of the predeterminedpath.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects are better understood when the followingdetailed description is read with reference to the accompanyingdrawings, in which:

FIG. 1 is a side view of an example embodiment of an apparatus includinga robotic arm and used to process an example work piece;

FIG. 2 is a perspective view of an example embodiment of a mountingassembly that is attached to a distal end of the robotic min andincludes a sealant discharger and a plasma discharger;

FIG. 3 is a first side view of the mounting assembly including thesealant discharger and the plasma discharger;

FIG. 4 is a second side view of the mounting assembly;

FIG. 5 is a top view of the mounting assembly;

FIG. 6 is a perspective view of the work piece including a surface onwhich a predetermined path along which sealant is to be applied; and

FIG. 7 is a schematic top, close up view of the surface showing thefirst point and the second point at multiple positions tracing thepredetermined path.

DETAILED DESCRIPTION

Examples will now be described more fully hereinafter with reference tothe accompanying drawings in which example embodiments are shown.Whenever possible, the same reference numerals are used throughout thedrawings to refer to the same or like parts. However, aspects may beembodied in many different forms and should not be construed as limitedto the embodiments set forth herein.

Referring now to FIG. 1, an example embodiment of an apparatus 10 usedto process work pieces 100 is illustrated. The apparatus 10 may be partof an assembly line (not shown) that includes various types of robotsfor processing work pieces 100 which may be components that areassembled into completed goods. In order to provide the apparatus 10with the mobility to handle the goods, the apparatus 10 may include arobotic arm 12 with joints that allow a distal end 14 of the robotic arm12 to reach or extend to a range of areas around a work piece. Forexample, the robotic arm 12 may include a plurality of members that arerotatably coupled at the joints so as to be pivotable around a pluralityof axes and may be configured as a 6-axis or 7-axis robot.

A variety of tools may be attached to the distal end 14 to perform avariety of processes on the work piece 100 such as transporting the workpiece, inserting parts into the work piece, screwing/unscrewing,injecting material onto the work piece, or the like. The apparatus 10may include a mounting assembly 16 that is attached to the distal end 14of the robotic arm 12 in order to mount one or more tools on the distalend 14 of the apparatus 10. In the present embodiment, the apparatus 10is configured to apply sealant on the work piece 100 and to clean asurface of the work piece 100 prior to applying the sealant. Moreover,the distal end 14 may be embodied as a substantially cylindrical part ofthe robotic arm 12 and may have an axis 18 around which the distal end14 is rotatable with respect to the robotic arm 12. The mountingassembly 16 may be mounted to the distal end 14 so as to be rotatablearound the axis 18. For example, the distal end 14 may include agripping element while the mounting assembly 16 may include a grippedelement that is engaged or becomes interlocked with the grippingelement.

Furthermore, the mounting assembly 16 may allow a sealant discharger 20and a plasma discharger 22 to be mounted to or dismounted from thedistal end 14 and may include a variety of structures to align andmaintain the sealant discharger 20 and the plasma discharger 22 indesired orientations. In the embodiment shown in FIGS. 2-5, the mountingassembly 16 includes a main plate 24, an end plate 26, a first mountingplate 28 and a second mounting plate 30. The distal end 14 may includean end face (not shown) on which the end plate 26 may be secured to. Themain plate 24 may be oriented to be substantially perpendicular to theend plate 26 so as to be parallel to the axis 18. A gusset 32 may beused to strengthen the connection between the end plate 26 and the mainplate 24. The sealant discharger 20 may be mounted near a first face 24a (FIG. 3) of the main plate 24 while the plasma discharger 22 may bemounted near a second face 24 b (FIG. 2) of the main plate 24 that isopposite the first face 24 a. The sealant discharger 20 may be attachedon top of the first mounting plate 28 secured to the first face 24 a ofthe main plate 24 as shown in FIG. 4. The plasma discharger 22 may beattached to a second mounting plate 30 that may be secured to the mainplate 24 so as to project therefrom as shown in FIG. 2.

As shown in FIGS. 3-4, the sealant discharger 20 may include a sealantnozzle 34 with a sealant outlet 36 at the end thereof and from which atype of sealant may be discharged onto a surface of the work piece 100.The sealant discharger 20 may thus be in fluid communication with asealant tank (not shown) supplying the sealant as needed according to asealant discharge controller (not shown). The sealant may be of a typesuitable for adhering the assembled components onto each other. Thesealant discharger 20 may be mounted on the distal end 14 so that alongitudinal axis of the sealant nozzle 34 is coaxially aligned with theaxis 18 around which the distal end 14 is rotatable as shown in FIG. 1.

The plasma discharger 22 may include a plasma nozzle 38 with a plasmaoutlet 40 from which gas in a plasma state is discharged so as to removeimpurities and contaminants from a surface of the work piece 100. Theplasma discharger 22 may thus be in fluid communication with a gas tank(not shown) containing a type of gas that can be excited to a highenergy, plasma state. The plasma may be supplied and discharged asneeded according to a plasma discharge controller (not shown). Theplasma discharger 22 may be mounted on the distal end 14 so that theplasma nozzle 38 is located a distance apart from the axis 18 of thedistal end 14. In the present embodiment, the plasma discharger 22 issecured to the second mounting plate 30 so as to be at an angle relativeto the sealant discharger 20.

Under the configuration shown in FIGS. 1-5, the sealant flows along theaxis 18 of the distal end 14 and is also discharged along the axis 18because the sealant nozzle 34 is longitudinally aligned with the axis 18and the sealant outlet 36 is located on the axis 18. Thus, the sealantmay be discharged along the axis 18 from a first point 42 positioned onthe axis 18 as shown in FIG. 3. Moreover, the longitudinal axis 19 ofthe plasma nozzle 38 may be oriented to be at an angle relative to theaxis 18 with which the sealant nozzle 34 is aligned and may also be adistance apart from the axis 18 such that the plasma outlet 40 ispositioned at a second point 44 which is the same distance apart fromthe axis 18 (FIG. 3). As shown in. FIGS. 2-5, the axis 18 to which thesealant nozzle 34 is aligned and the axis 19 to which the plasma nozzle38 is aligned are oriented such that the axes 18, 19, and extensionsthereof to, do not intersect. Because of the aforementioned arrangementof the sealant discharger 20 and the plasma discharger 22, the secondpoint 44 can be rotated around the axis 18 or the first point 42 uponrotation of the distal end. 14 around the axis 18. The first point 42and the second point 44, which define discharge points for sealant andplasma respectively, are sufficiently in proximity to the surface of thework piece 100 so that the sealant and the plasma respectively areapplied at the intended portions of the work piece 100.

Referring to FIGS. 6-7, the apparatus 10 can be controlled in thefollowing manner to apply sealant on a surface 102 of a work piece 100while cleaning the surface 102 by way of plasma prior to applying thesealant. An example of a work piece 100 that can be processed by theapparatus 10 is shown in FIG. 6 and may be a component for an engineblock, for example. While the surface 102 of the work piece 100 may beflat as shown in FIG. 6 so as to lie in a plane, the surface 102 mayalso have three-dimensional surface textures and may include bumps,recesses, undulations or the like, for example. Moreover, the surface102 may be located along the outer edges of the work piece 100 and mayextend along a perimeter of the work piece 100 as shown in FIG. 6. Therobotic arm 12 of the apparatus 10 can be programmed such that sealantis applied along a predetermined path 104 extending along the perimeteras shown in FIG. 6 on the surface 102 of the work piece 100. In theexample work piece of FIG. 6, the predetermined path 104 is shaped to goaround holes 106 formed for bolts/screws. Moreover, while thepredetermined path 104 of FIG. 6 forms a closed loop, the predeterminedpath 104 may simply include a starting point and an end point.

In order to apply the sealant, the robotic arm 12 may be controlled suchthat both of the first point 42 and the second point 44 trace thepredetermined path. In one example method of controlling the robotic arm12, this may be accomplished by positioning the sealant discharger 20and the plasma discharger 22 such that the axis 18 of the distal end 14intersects the predetermined path 104 while maintaining the axis 18 at asubstantially perpendicular orientation relative to the surface 102 ofthe work piece 100, moving the axis 18 along the predetermined path 104,and pivoting the second point 44 around the axis 18 or the first point42 as the axis 18 is moving along the predetermined path 104 such thatthe second point 44 traces the predetermined path 104 as the first point42 traces the predetermined path 104. FIG. 7 shows a plurality ofpositions A, B, C and D for the distal end 14 and the locations of thefirst point 42 and the second point 44 corresponding to each of thesepositions which are reached using the aforementioned steps. The term‘pivoting’ is meant to be distinguished from the term. ‘rotating’ inthat pivoting involves movement of an element that is rotatable aroundan axis where the rotational direction is frequently changed whereasrotating involves movement of an element that is rotatable around anaxis where the rotational direction is maintained in one direction. Thesecond point 44 is pivoted around the axis 18 because, depending on theshape of the predetermined path 104, the rotational direction may needto be frequently altered in order for both of the first point 42 and thesecond point 44 to trace the predetermined path 104. The distancebetween the first point 42 and the second point 44 is sized to allow thefirst point 42 and the second point 44 to be simultaneously located onthe predetermined path 104 as shown in FIG. 7. For example, when thefirst point 42 and the second point 44 are moving along a curved portionof the predetermined path 104 having a small radius of curvature, it maynot be possible for both of the first point 42 and the second point 44to be located on the predetermined path 104 if this distance is toolarge. However, the apparatus 10 may be configured such that thedistance between the first point 42 and the second point 44 isadjustable depending on the curvatures of the predetermined path 104.

Because the sealant discharger 20 is mounted on the distal end 14 suchthat the first point 42 from which sealant is discharged is located onthe axis 18, the movement of the axis 18 of the robotic arm 12 along thepredetermined path 104 results in the first point 42 tracing thepredetermined path 104 and application of the sealant along thepredetermined path 104. Moreover, as the robotic arm 12 is moved suchthat the first point 42 from which sealant is discharged traces thepredetermined path 104, the distal end 14 is pivoted as needed such thatthe second point 44 from which plasma is discharged traces thepredetermined path 104 while moving ahead of the first point 42 duringthe entirety of the movement of the axis 18 along the predetermined path104. In order for both the first point 42 and second point 44 to tracethe predetermined path 104 as the distal end 14 is moved along thepredetermined path 104, the distal end 14 may proceed in the directionof the arrow of FIGS. 3 and 7 when moving along the predetermined path104. Because the second point 44 moves ahead of the first point 42during the entirety of the predetermined path 104, plasma is dischargedonto a part of the surface 102 before sealant is discharged on the samepart and the discharged plasma does not burn off sealant that hasalready been applied and removes impurities, contaminants or the likefrom the surface to allow for more effective application of the sealant.

The apparatus 10 may be operated using a controller (not shown) that canbe programmed to move the distal end 14 so that the first point 42 andthe second point 44 trace the predetermined path 104. For example, anoperator may move the distal end 14 such that the first point 42 and thesecond point 44 assume a plurality of positions (e.g., A, B, C and D inFIG. 7) along the predetermined path 104. The controller may be equippedwith the capability to memorize the plurality of positions of the firstpoint 42 and the second point 44 within the predetermined path 104indicated by the operator and may interpolate other positions of thefirst point 42 and the second point 44 within the predetermined path 104so as to move the distal end 14 so that the first point 42 and thesecond point 44 trace the predetermined path 104. A sufficiently highnumber of positions would need to be memorized by the controller inorder to precisely trace the predetermined path 104. The apparatus 10may be provided with an interface by way of which the operator canprogram the controller to memorize a plurality of positions of thedistal end 14 along the predetermined path 104 with correspondinglocations through which the first point 42 and the second point 44 needto move through (FIG. 7). After the controller has memorized theplurality of positions set by the operator, the remaining positionsalong the predetermined path 104 may be determined by the controllerthrough interpolation and the robotic arm 12 operates to move the distalend 18 along the predetermined path 104.

Using the aforementioned method of controlling the robotic arm 12, it iseasy to program the robotic arm 12 such that the predetermined path 104is traced by the first point 42 because the first point 42 is located onthe axis of the distal end 14 which is one of the axis 18 by which themovement of the robotic arm 12 is typically controlled and consequentlythe tracing of the predetermined path 104 by the first point 42 and thesecond point 44 is facilitated.

It will be apparent to those skilled in the art that variousmodifications and variations can be made without departing from thespirit and scope of the claimed apparatus or method.

What is claimed is:
 1. A mounting assembly configured to attach a plasmadischarger and a single sealant discharger to a robotic arm, comprising:a plasma discharger; a sealant discharger; a main plate having a firstface and a second face opposite the first face; an end plate, whereinthe main plate is oriented substantially perpendicular to the end plate;a first mounting plate extending from the first face of the main plateand configured to engage the sealant discharger so that a longitudinalaxis of the sealant discharger is aligned with a first axis of therobotic arm; a second mounting plate extending from the second face ofthe main plate and configured to engage the plasma discharger so thatthe plasma discharger is capable of rotating about the first axis;wherein the sealant discharger is configured to discharge sealant at afirst point, the first point being positioned on the longitudinal axisof the sealant discharger; and wherein the plasma discharger isconfigured to discharge plasma at a second point that is located adistance apart from the longitudinal axis of the sealant discharger, thesecond point being positioned on a longitudinal axis of the plasmadischarger and oriented to be at an angle relative to the longitudinalaxis of the sealant discharger such that the longitudinal axis of theplasma discharger and the longitudinal axis of the sealant dischargerand extensions thereof do not intersect.
 2. The mounting assembly ofclaim 1, further comprising a gripped element configured to engage agripping element on the robotic arm.
 3. The mounting assembly of claim1, further comprising a gusset connecting the main plate and the endplate.
 4. The mounting assembly of claim 1, wherein the first mountingplate is secured to the first face of the main plate and the sealantdischarger is attached to the first mounting plate.
 5. The mountingassembly of claim 1, wherein the second mounting plate is secured to thesecond face of the main plate and the plasma discharger is attached tothe second mounting plate so as to project therefrom.
 6. A mountingassembly with a plasma discharger and a single sealant dischargerattached to a robotic arm so that the mounting assembly is rotatableabout a first axis of the robotic arm, comprising: a main plate having afirst face and a second face that is opposite the first face; an endplate, wherein the main plate is oriented perpendicular to the endplate; a first mounting plate extending from the first face of the mainplate and configured to engage the sealant discharger so that a firstpoint defining a discharge point for sealant is positioned on the firstaxis; a second mounting plate extending from the second face of the mainplate and configured to engage the plasma discharger in a fixedorientation with respect to the sealant discharger, so that the plasmadischarger discharges plasma at a second point that is located adistance apart from the first axis, wherein the second point ispositioned on a longitudinal axis and oriented to be at an anglerelative to the first axis of the robotic arm such that the longitudinalaxis and the first axis of the robotic arm and extensions thereof do notintersect.
 7. The mounting assembly of claim 6, further comprising agripped element extending from the end plate and configured to engage agripping element on the robotic arm.
 8. The mounting assembly of claim6, further comprising a gusset connecting the main plate and the endplate.